The Hennepin County Attorney’s Office said Timothy Marshall pleaded guilty to one count of attempted second-degree murder and multiple counts of assault. He is likely to receive a sentence of 55 months in prison.

The assault happened on Oct. 28, 2011, at the Hennepin County Medical Center. Marshal followed a lab technician into a restroom and attacked her from behind. He put the woman in a choke hold, dragged her to the floor and punched her repeatedly in the head.

Marshall only released the victim after another person walked into the bathroom and pulled him off.

Marshall is slated to be sentenced on July 9, the attorney’s office said.